Update, May 3, 2020 The indications — not proof yet! — are that larger-droplet infection is the main route of transmission. Probably not the only one, aerosols (small, floating droplets) and surfaces still require caution, but larger droplets seem to be the main one. In news-you-can-use, that means physical distancing and masks, any masks, including folded tea towels, are the two most important preventive behaviors.
1) The importance of social distancing, self-quarantining, self-isolating, and the like:
The general idea is to stay at least 3ft / 1m away from other people, preferably 6ft / 2m. The virus is less contagious than some, so unlike measles, you’re unlikely to catch just from walking past a carrier in the grocery store. Updated to add: Info from Dr. Nancy Jin via LATimes, median risk of infection at 15 minutes of close face-to-face time (eg packed in a checkout line buying toilet paper), or two hours in a contained environment (eg class, bus, travel, meetings at work).
And of course, wash hands, wash hands, wash hands. You’ve heard that enough by now and know how to do it.
Short version if you have no other medical issues: have Tylenol 325mg (acetaminophen, paracetamol) and/or Advil 200mg (ibuprofen) handy to manage fever. Have a cough suppressant + expectorant on hand, like Robitussin DM or anything similar. Tissues. Make yourself soup that you can freeze (or buy cans of what you like). You won’t want to cook. Stay hydrated! Drink like a fish. This is a lung disease, so humidified air feels better. If you have no humidifier, one workaround is to sit in the bathroom with a hot shower going.
Call ahead to emergency services only if the fever gets too high despite meds (not sure what that level is, over 101F? need to find out!) and if you can’t breathe. I.e. you’re in serious trouble without oxygen or a ventilator.
3) And because knowing how far and how fast it’s spreading and where it’s coming under control are potentially useful: a real time tracker of the incidence of cases.